PCR-based detection of genes encoding virulence determinants in Staphylococcus aureus from birds

Area of Science:

• Veterinary Microbiology
• Molecular Biology
• Infectious Diseases

Background:

• Staphylococcus aureus is a versatile pathogen with zoonotic potential.
• Avian strains of S. aureus can cause significant disease in poultry and wild birds.
• Understanding the genetic basis of virulence in avian S. aureus is crucial for disease control.

Purpose of the Study:

• To genetically characterize Staphylococcus aureus strains isolated from diverse avian sources.
• To investigate the distribution of specific virulence factor genes within these avian isolates.
• To provide a foundation for understanding the role of these determinants in avian pathogenesis.

Main Methods:

• Genotypic characterization of 19 S. aureus isolates from avian specimens.
• Polymerase chain reaction (PCR) amplification using 62 oligonucleotide primers.
• Detection of genes encoding cell surface proteins, exoproteins, and accessory gene regulator (agr) classes.

Main Results:

• All 19 isolates possessed S. aureus-specific 23S rRNA, nuc, clfA, coa, and spa genes.
• Genes hla and fnbA were universally present, while seb, sec, sed, see, sej, tst, eta, and etb were absent.
• Variable presence of other virulence genes including sbi, hlb, fnbB, cna, cap5/8, and agr classes was observed.

Conclusions:

• Avian S. aureus strains share core virulence genes essential for identification and basic pathogenicity.
• The absence of specific toxin genes suggests distinct pathogenic profiles compared to some human strains.
• This genotypic data aids in understanding S. aureus virulence in avian hosts and potential transmission dynamics.